Tubing assembly and signal generator placement control device and method for use with catheter guidance systems

ABSTRACT

A tubing assembly having a signal generator placement control device for use in conjunction with electronic catheter guidance systems. The control device facilitates control of the position the guidance systems&#39; signal generator relative to the end of the tubing assembly. The tubing assembly includes a tubular insulator coupled to one end of the control device, and the tubing assembly includes a tubular connector attached to the other end of control device. Also, the tubing assembly includes a catheter attached to the tubular connector and an end member attached to the catheter.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of, and claims priority to U.S. application Ser. No. 14/852,775, filed Sep. 14, 2015, which is a continuation of U.S. application Ser. No. 13/151,882, filed Jun. 2, 2011, now U.S. Pat. No. 9,131,956, issued Sep. 15, 2015, which is a continuation of U.S. application Ser. No. 11/036,514 filed Jan. 13, 2005, now U.S. Pat. No. 7,976,518, issued Jul. 12, 2011, the entire content each of which is hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

Physicians and other health care providers frequently use catheters to treat patients. The known catheters include a tube which is inserted into the human body. Certain catheters are inserted into through the patient's nose or mouth for treating the gastrointestinal tract. These catheters, sometimes referred to as enteral catheters, typically include feeding tubes. The feeding tube lies in the stomach or intestines, and a feeding bag delivers liquid nutrient, liquid medicine or a combination of the two to the patient.

Other types of catheters are inserted into the patient's veins or arteries for treating the cardiovascular system. These catheters include, among others, the central venous catheter, peripheral venous catheter and the peripherally inserted central catheter (PICC). These catheters include a relatively small tube that passes through the patient's veins or arteries. The health care provider uses these catheters to provide patients with injections of medications, drugs, fluids, nutrients, or blood products over a period of time, typically several weeks or more.

When using these known catheters, it is important to place the end of the catheter at the proper location within the human body. Erroneous placement of the catheter tip may injure or harm the patient. For example, if the health care provider erroneously places an enteral catheter into the patient's lungs, liquid may be introduced into the lungs with harmful results. If the health care provider erroneously places a catheter into the wrong cavity of the cardiovascular system, the patient may experience infection or a harmful blockage.

In some cases, health care providers use X-ray machines to gather information about the location of the catheters within the body. There are several of disadvantages with using X-ray machines. For example, these machines are relatively large and heavy, consume a relatively large amount of energy and may expose the patient to a relatively high degree of radiation. Also, these machines are typically not readily accessible for use because, due to their size, they are usually installed in a special X-ray room. This room can be relatively far away from the patient's room. Therefore, health care providers can find it inconvenient to use these machines for their catheter procedures. Furthermore, it can be inconvenient to transport these machines to a patient's home for home care catheter procedures.

Accordingly, there is a need to overcome each of these disadvantages.

SUMMARY OF THE INVENTION

The present invention generally relates to a tubing assembly for a catheter position guidance system. The catheter guidance system is used to help guide a catheter to a position located within the body. The system can be used during enteral, parenteral or other suitable catheter feeding applications.

In one embodiment, the catheter guidance system includes a signal generator attached to the end of a wire assembly or stylet. The tubing assembly of the present invention houses the signal generator and the stylet while the signal generator is in the body. The tubing assembly includes a tubular insulator, a mid-connector or union device which is connected to the tubular insulator, a y-port connector that attaches to the union device and a feeding tube or other catheter connected to the y-port connector.

The mid-connector or union device enables assemblers to conveniently set the position of the signal generator at the proper location within the catheter. This function of the union device enables a stylet of a set length to be used with catheters of variable lengths. Therefore, the tubing assembly, used in conjunction with the catheter position guidance system of the present invention, provides an enhancement in catheter placement during medical treatment.

It is therefore an advantage of the present invention to provide a tubing assembly and signal generator placement control device and method for use with catheter guidance systems.

Another advantage of the present invention is to assist the user in properly placing a catheter end within the body.

Still another advantage of the present invention is to reduce the amount of time necessary to properly guide a catheter to a desired cavity within the body.

Yet another advantage of the present invention is to reduce the amount of radiation exposure associated with machines that assist in catheter placement.

Another advantage of the present invention is to reduce the likelihood of harm caused by placing a catheter within the body.

Yet another advantage is to simplify the process of catheter placement procedures.

Still another advantage of the present invention is to increase the safety of catheter placement procedures.

Another advantage of the present invention is to adapt catheters of variable lengths to receive an electronic stylet of a pre-set length.

Yet another advantage of the present invention is to assist health care providers in guiding and locating catheters within the body at the patient's bedside.

Another advantage of the present invention is to increase the convenience of obtaining catheter placement information during and after placement of a catheter.

Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of the catheter position guidance system illustrating the display device, electronic catheter unit and hand-held transceiver being used to position a catheter within a patient in one embodiment of the present invention.

FIG. 2 is schematic block diagram of the electronic configuration of the catheter position guidance system illustrating the processor, memory device, signal generator, input devices and output devices in one embodiment of the present invention.

FIG. 3 is a top or plan view of the electronic catheter unit and the display device illustrating an enteral application involving a catheter inserted into a human body and indication of catheter information on the display device.

FIG. 4 is a top or plan view of the electronic catheter unit and the display device illustrating a parenteral application involving a catheter inserted into a human body and indication of catheter information on the display device.

FIG. 5 is a perspective view of the electronic catheter unit illustrating the tubing assembly and the signal generator being received by and housed in the tubing assembly in one embodiment of the present invention.

FIG. 6 is a perspective view of the electrical connector of the electronic catheter unit removed from the tubing assembly illustrating the tubular connection, union device, y-port connection, feeding tube and tip of the tubing assembly in one embodiment of the present invention.

FIG. 7 is a cross-section view of the tubular insulator housing the wire assembly taken substantially along line VII-VII of FIG. 5.

FIG. 8A is a perspective view of the union device in one embodiment of the present invention.

FIG. 8B is a cross-section view of the generator position control device or union device taken substantially along line VIIIB-VIIIB of FIG. 8A.

FIG. 9 is a top or plan view of the proximal end of the union device in one embodiment of the present invention.

FIG. 10 is a perspective view of the y-port connector illustrating the feeding branch, medicine branch, connection branch and flexible arms in one embodiment of the present invention.

FIG. 11 is a cross-section of the y-port connector taken substantially along line XI-XI of FIG. 10.

FIG. 12 is a perspective view of the y-port connector and feeding tube attached to the connection branch of the y-port connector in one embodiment of the present invention.

FIG. 13 is a perspective view of the end member or tip of the catheter in one embodiment of the present invention.

FIG. 14 is a perspective view of the signal generator illustrating the tubular insulator housing a portion of the wire assembly in one embodiment of the present invention.

FIG. 15 is a perspective view of the electrical connector of the signal generator illustrating the electrical connector coupled to the electrical extension extending from the housing in one embodiment of the present invention.

FIG. 16 is a top perspective view of the electrical connector of the signal generator illustrating the top and bottom surfaces, circuit board, the contact members on the circuit board, the copper wires attached to the contact members and the elongated stiffener in one embodiment of the present invention.

FIG. 17 is a bottom view of the electrical connector of the signal generator in one embodiment of the present invention.

FIG. 18 is a top or plan view of the circuit board of the electrical connector of the signal generator in one embodiment of the present invention.

FIG. 19 is a perspective view of the signal generator in one embodiment of the present invention.

FIG. 20 is a perspective view of the magnetic field generator illustrating the coils surrounding the signal booster in one embodiment of the present invention.

FIG. 21 is a top or plan view of an electronic catheter not having the stop member or position controller of the present invention illustrating an example of a magnetic field generator improperly extending beyond the opening of the catheter.

FIG. 22 is another view of an electronic catheter not having the stop member or position controller of the present invention illustrating an example of a signal generator improperly positioned with respect to the opening of the catheter.

FIG. 23 is a top or plan view of different sized catheters illustrating varying positions of the magnetic field generator near the tip of the catheter due to manufacturing variations among the catheters.

FIG. 24 is a perspective view of the union device and the tubular insulator illustrating a user inserting the distal end of the tubular insulator into the union device.

FIG. 25 is a perspective view of the union device and the tubular insulator illustrating a user adjusting the position of the magnetic field generator within the feeding tube by placing the distal end of the tubular insulator at various positions within the union device.

DETAILED DESCRIPTION OF THE INVENTION I. Catheter Position Guidance System

Referring now to the drawings, in an embodiment illustrated in FIGS. 1 and 2, the catheter position guidance system or catheter guidance system 2 includes: (a) an apparatus 10 having a housing 18 which supports a controller or processor 20 and a display device 22; (b) a non-invasive movable receiver-transmitter or transceiver 32 electronically coupled to the processor 20 by a wire, cable, signal data connection or signal carrier 62; (c) a power chord 27 that couples the apparatus 10 to a power source 25; (d) a printer 28 coupled to the apparatus 10 for printing out paper having graphics which indicate catheter location information; and (e) an invasive electronic catheter unit 12 in communication with the transceiver 32 and operatively coupled to the apparatus 10 by a wire, cable, chord or electrical extension 34, which, in turn, is operatively coupled to the processor 20. It should be appreciated that the transceiver 32 can include a device which has a separate signal receiver and signal transmitter. The transceiver 32 can also include a single device which functions so as to receive and transmit signals.

As best illustrated in FIG. 2, the system 2, in one embodiment, includes: (a) a plurality of input devices 17 for providing input signals to the system 2 such as one or more control buttons 29, a touch screen 31 and the transceiver 32; (b) a signal generating assembly 16 which produces or generates electronic signals that are received by the transceiver 32; (c) a memory device 21 including machine readable instructions and one or more computer programs (which, for example, may include a plurality of algorithms 23) which are used by the processor 20 to process the signal data produced by the signal generating assembly 16 and transmitted by the transceiver 32; and (d) a plurality of output devices 19 such as the display device 22 and the printer 28 which indicate the catheter information to the health care provider. The display device 22 may be any suitable display mechanism including, but not limited to, a liquid crystal display (LCD), light-emitting diode (LED) display, cathode-ray tube display (CRT) or plasma screen.

Health care providers can use the system 2 in a variety of catheter applications. In one example illustrated in FIG. 3, the system 2 is used in an enteral application. Here, a portion 70 of the electronic catheter unit 12 is placed through the patient's nose or mouth 72. The distal end or tip 60 of the unit 12 is positioned in the stomach 74. The health care provider places the transceiver 32 over the chest area 76 of a body 78. The display device 22 and the printer 28 indicate information related to the location of the portion 70 of the electronic catheter unit 12 within the body 78, as well as information related to the shape of the pathway taken by the catheter unit 12. It should be appreciated that the system 2 need not indicate the exact location or path of the catheter unit 12 to provide assistance to the health care provider.

In another example illustrated in FIG. 4, a portion 71 of the electronic catheter unit 12 is introduced into the patient's body 78 through a vein or artery 73 leading to the heart 75. Similar to the enteral example, the system 2 assists the health care provider in guiding the portion 71 of the unit 12 in the patient's vein or artery 73 to a desired cavity in the heart 75 in preparation for parenteral feeding.

II. Electronic Catheter Unit

Referring to FIG. 5, in one embodiment, the electronic catheter unit 12 includes a tubing assembly 14 which receives and houses the signal generating assembly 16.

A. Tubing Assembly

As best illustrated in FIGS. 6-7, in one embodiment, the tubing assembly 14 includes: (a) a tube or an electrical tubular insulator 40; (b) a mid-connector or union device 42 which receives the tubular insulator 40; (c) a multi-port connector or y-port connector 44 attachable to the union device 42; (d) a catheter 50, such as a feeding tube, connected to the y-port connector 44; and (e) a catheter end, bolus or tip 60 attached to the distal end of the catheter 50.

In one embodiment, the tubular insulator 40 includes a tube having: (a) a proximal end 100 attachable to an attachment member or neck 108 of the electronic catheter unit 12; (b) a distal end 102 receivable by the union device 42; (c) an internal diameter 104 which is substantially equal to or greater than an external diameter 110 of a wire assembly 38 described below so as to slide over the wire assembly 38; and (d) an external diameter 106. In another embodiment, the tubular insulator 40 may fit relatively tightly over the wire assembly 38 so as to be secured to the wire assembly 38.

As best illustrated in FIGS. 8A, 8B and 9, in one embodiment, the union device 42 includes: (a) a proximal end 116; (b) a distal end 118; (c) a position adjuster, extender or elongated neck 120 positioned between the proximal end 116 and the distal end 118; (d) a grasp or gripping member 122 positioned adjacent to the distal end 118 so as to assist users in grasping and manipulating the union device 42; (e) an insert 124 positioned adjacent to the gripping member 122 which is received by the y-port connector 44; and (f) an internal surface 126 having a blocking member or stop 132 which prevents the tubular insulator 40 from passing through the end 118. The gripping member 122 includes a plurality of protruding walls or ribbed members 136 protruding from a surface 123 of the gripping member 122 assisting the user in grasping the union device 42. In alternative embodiments, the surface 123 of the gripping member 122 may be rough or include other suitably shaped protrusions.

The proximal end 116 of the union device 42 has an internal diameter 128 and an external diameter 130. When assembled, the proximal end 116 of the union device 42 is coupled to the distal end 102 of the tubular insulator 40. In one embodiment, the internal diameter 128 of the proximal end 116 of the union device 42 is substantially equal to or larger than the external diameter 106 of the distal end 102 of the tubular insulator 40. Referring back to FIG. 6, this enables a portion 103 of the distal end 102 of the tubular insulator 40 to be movably received by the elongated neck 120 of the union device 42. As described above, the stop 132 (having a diameter 133) of the union device 42 prevents the distal end 102 of the tubular insulator 40 from passing through the distal end 118 of the union device 42.

Referring to FIGS. 10-11, in one embodiment, the multi-port or y-port connector 44 includes: (a) a body 140; (b) a liquid delivery branch, medicine delivery branch or medicine branch 142 attached to the body 140 for distributing drugs, medicine or other medicinal liquids to the patient; (c) a nutrient delivery branch or feeding branch 144 attached to the body 140 and sized to receive the insert 124 of the union device 42; (d) a catheter or feeding tube connection branch 146 attached to the catheter 50; (e) a flexible or movable arm 148 attached to the body 140; and (f) a flexible or moveable arm 150 attached to the body 140. In an alternative embodiment, y-port connector 44 includes additional branches for administering various nutrients or medicines to the body 78. In another alternative embodiment, the y-port connector 44 includes only a feeding branch 144 and a connection branch 146. The arm 148 has a stopper 152, and the arm 150 has a stopper 154. The stoppers 152 and 154 are sized to prevent fluid from passing through the branches 142 and 144 after such branches 142 and 144 are plugged with stoppers 152 and 154, respectively. In addition, the arm 150 includes a fastener 155 which secures a tube-size adapter 156 to the arm 150. The tube-size adapter 156 enables fluid delivery tubes (not shown) having various diameters to connect to the feeding branch 144 of the y-port connector 44.

As illustrated in FIGS. 12-13, in one embodiment, the catheter 50 includes a feeding tube with a body 160 having: (a) a proximal end 162 attached to the catheter connection branch 146 of the y-port connector 44; (b) a distal end 164; and (c) an external surface 166. The proximal end 162 is insertable into the catheter connection branch 146 of the y-port connector 44 so as to bring the catheter 50 into fluid communication with the y-port connector 44. In one embodiment, the external surface 166 has a plurality of volumetric, measurement or unit markings 168 uniformly spaced along the body 160 of the catheter. These markings 168 assist the user in measuring the flow or distribution of liquid to or from the patient. In an alternative embodiment, markings 168 function as placement markers which assist the user in assessing the depth that the catheter is placed within the human body.

As best illustrated in FIG. 13, in one embodiment, the end member, bolus or tip 60 is attached to the distal end 164 of the catheter 50. The tip 60 includes a body 172 having a collar 174 and an end member 176. The body 172 defines a passage 178 and an opening 180. The opening 180 is positioned between the collar 174 and the end member 176. A portion 177 of the end member 176 can have a rounded shape. The shape of the passage 178 and opening 180 of the tip 60 is configured to facilitate the flow of fluid from the catheter 50 into the patient's body while decreasing the likelihood that the opening 180 will become clogged.

The tubular connector 40, union device 42, y-port connector 44, catheter and tip 60 can be made from any suitable polymer or plastic material including, but not limited to, polyamide, polyethylene, polypropylene, polyurethane, silicone and polyacrylonitrile.

B. Signal Generating Assembly

As best illustrated in FIGS. 14-21, in one embodiment, the invasive signal generating assembly 16 includes: (a) a controller coupler or an electrical connector 36 operatively connected to the electrical extension 34; (b) an elongated wire assembly 38 operatively coupled to the connector 36; (c) a wire or elongated stiffener 39 attached to the connector 36 and serving as a support for the wire assembly 38; (d) a magnetic energy generator or magnetic field generator 58 operatively coupled to the distal end of the wire assembly 38; and (e) a suitable fastener attaching the distal end of the elongated stiffener 39 to the magnetic field generator 58. The tubular insulator 40**** described above covers a portion 41 of the wire assembly 38 positioned adjacent to the connector 36.

1. Electrical Connector

As best illustrated in FIGS. 16-18, in one embodiment, the electronic or electrical connector 36 includes: (a) a top wall or surface 186; (b) a side wall or surface 188 attached to the top surface 186; (c) a bottom wall or surface 189 attached to the side wall 188; (d) an electronic lead assembly or electronic connector 190, such as a circuit board 191, positioned between the top surface 186 and the bottom surface 189; and (e) fasteners 192 and 194 attaching the top surface 186 to the bottom surface 189. It should be appreciated that various fasteners may be used to secure the top surface 186 to the bottom surface 189. The fasteners 192 and 194 may be mechanical or chemical. Mechanical fasteners may, for example, include snaps, screws, rivets or other suitable fasteners. Chemical fasteners may include, for example, adhesives, chemical bonds, weld bonds or moldings suitable for securing the top surface 186 and the bottom surface 189 together. Although the embodiment illustrated in FIG. 16 has multiple fasteners 192 and 194 passing through the circuit board 191, it should be understood that, in other embodiments, a single fastener may securely position the circuit board 191 between the two surfaces 186 and 189.

The circuit board 191, in one embodiment, includes: (a) contact members 196 and 198 extending across a portion 193 of the circuit board 190; and (b) a reserve contact member 200 extending across the circuit board 190. The contact members 196, 198 and 200 can be made from any conductive materials. When the electronic connector 190 is connected to the electrical extension 34, the contact members 196, 198 and 200 are operatively coupled to the apparatus 10 of the system 2. Therefore, the contact members 196 and 198 transmit electrical current from the apparatus 10 to the magnetic energy generator or magnetic field generator 58 described below.

2. Wire Assembly

As best illustrated in FIGS. 16, 18 and 21, in one embodiment, the wire assembly 38 includes: (a) an elongated flexible conductor such as a copper wire 202 having a proximal end 206 connected to the circuit board 190 and a distal end 251 connected to the magnetic field generator 58; and (b) another elongated flexible conductor such as a copper wire 204 having a proximal end 212 connected to the circuit board 190 and a distal end 253 connected to the magnetic field generator 58. In one embodiment, the copper wire 202 and copper wire 204 include a polymeric coating 218. The proximal end 206 of the copper wire 202 is operatively coupled to an extension 197 of the contact member 196 of the circuit board 191. Likewise, the proximal end 212 of the copper wire 204 is operatively coupled to an extension 199 of the contact member 198 of the circuit board 191. The copper wires 202 and 204 can be soldered to the appropriate contact members 196 and 198 or attached by any suitable fastener.

In one embodiment described below, the distal ends 251 and 253 of the copper wires 202 and 204 have a coil configuration forming coils 250 thereby producing a magnetic field generator 58 as described below. The coil 248 is formed from a plurality of spirals 252 produced by wrapping a portion 249 of the copper wire 204 around the magnetic field generator 58 as described below.

Referring back to FIG. 16, the copper wire 202 and the copper wire 204 are twisted around each other along the lengths 210 and 216 to form a twisted configuration 217. In one embodiment, the copper wires 202 and 204 are twisted a suitable number of times along the lengths 210 and 216. The twisted configuration 217 reduces any electromagnetic field surrounding the wires 202 and 204 along the twisted lengths 210 and 216. This reduction is caused by the counteraction of the electromagnetic forces of the electrical wires 202 and 204. Accordingly, the hand-held transceiver 32 receives less, if any, signal interference arising from any electromagnetic fields generated by the wire assembly 38.

As illustrated in FIG. 18, in one embodiment, the elongated stiffener 39 includes a bend or center portion 228. The elongated stiffener 39 is preferably made of steel but can be made of any other suitable material. The center portion 228 of the elongated stiffener 39 is looped around the fastener 192 of the connector 36 forming a segment 230 and a segment 232. The segments 230 and 232 are twisted around each other forming a twisted configuration 234. The twisted configuration 234 increases the rigidity of the elongated stiffener 39. In one embodiment, the wire assembly 38 is twisted into the grooves 219 of the twisted configuration 234. This increases the space efficiency of the wire assembly 38 and the elongated stiffener 39 positioned within the tubing assembly 14. The increase in space efficiency is a result of reducing the overall diameter 110 of the wire assembly 38, as illustrated in FIG. 7.

3. Signal Generator

As best illustrated in FIG. 20, in one embodiment, the signal generator or magnetic field generator 58 is formed through a plurality of spirals or coils 250 of the wires 202 and 204. As the apparatus 10 transmits electrical current through the wires 202 and 204, the current travels in a circular path defined by the coils 250. This circular motion of current produces an electromagnetic field, B field or electromagnetic radiation 258. Although the embodiment illustrated includes the coils 250 as the magnetic field generator 58, it should be appreciated that the magnetic field generator 58 can include any alternate suitable mechanism or device which generates or produces magnetic energy or a magnetic field. In one embodiment, the magnetic field generator 58 includes a magnet such as a permanent magnet, resistive magnet or superconducting magnet.

In operation, when the apparatus 10 sends electrical current to the coils 250, and the coils 250 transmit a signal or electromagnetic field 258 capable of being detected by the non-invasive transceiver 32. The transceiver 32 detects the electromagnetic field or signal 258 generated by the magnetic field generator 58 inside the human body. The processor 20 causes the display device 22 and the printer 28 to produce graphics which assist the health care provider in the catheter placement procedure.

C. Method of Controlling Placement of Signal Generator

As illustrated in FIGS. 21-25, several difficulties could arise if a catheter assembly 300 does not have the stop member 132 and position adjuster or controller 120 of the union member 42 of the present invention. For example, a catheter procedure may involve positioning the tip 60 of a catheter 50 to a desired location. During the manufacturing process for the catheters 50, the catheters 50 may have length variations V₁, V₂ and V₃ ranging up to one and one-fourth of an inch. In one embodiment, catheters 50 are constructed of a polyurethane material which provides the catheters 50 with a tendency to expand or contract during or after the manufacturing process thereby causing such variations. If one of the catheters 50 is too long, the magnetic field generator 58 could protrude through the tip 60 as illustrated in FIG. 21. If one of the catheters 50 is too short, the magnetic field generator 58 could substantially stop short of the tip 60 as illustrated in FIG. 22. This may result in a decrease in reliability of the information and graphics provided by the catheter position guidance system 2 of the present invention.

The system 2 is more helpful when the magnetic field generator 58 is positioned at or near the tip 60 of the catheter 50. This positioning helps maintain an adequate level of reliability of guidance information provided by the system 2. In the embodiments best illustrated in FIGS. 1-20 and 23-25, the union device 42 assists in maintaining the position of the magnetic field generator 58 at or near the tip 60. The use of the union device 42, in one such embodiment, reduces the likelihood that the magnetic field generator 58 might protrude through the tip 60 or stop substantially short of the tip 60. Therefore, the union device 42 functions as a generator placement control device. In one embodiment, this placement and control function of the union device 42 is adjustable to conform to catheters 50 that have different lengths.

As best illustrated in FIGS. 24-25, the union device 42 has a proximal end 116, a distal end 118 and a position controller, position adjuster or elongated neck 120. The proximal end 116 is movably coupled to the distal end 102 of the tubular insulator 40. The position adjuster or elongated neck 120 defines a passage 134 which provides the position adjustment function or adjustment device of the union device 42. The user can adjustably position the second end 102 of the tubular insulator 40 to a plurality of different locations 138 (for example, L1-L3) along the passage 134. Once the user determines the proper location 138, the user fixes the tubular insulator 40 to the position adjuster 120 at that selected location. The position may be fixed using an adhesive, clip, clasp, tape or any other suitable fastener. Because the tubular insulator 40 is connected to the electrical connector 36 which, in turn, is connected to the magnetic field generator 58, the fastening of the tubular insulator 40 to the proper location on the position adjuster 120 assists in the proper positioning of the magnetic field generator 58 relative to the tip 60 of the catheter 50. This allows the user to position the magnetic field generators 58 at a desired or designated location relative to the end members or tips 60 of catheters 50 of various lengths. Thus, users can use the system 2 with manufactured catheters 50 having various lengths.

In one example, the method of controlling the placement of the generator 58 includes first step of determining the length of the catheter 50. Next, prior to placing the catheter 50 into the human body for enteral or parenteral feeding, the user or assembler places the magnetic field generator 58 at a desired location within the catheter 50. Finally, the assembler locks this placement by fastening the tubular insulator 40 to the union device 42 using a suitable adhesive.

Once the position of the generator 58 has been properly set, the health care provider places the transceiver 32 on the patient's chest and inserts the catheter 50 into the body. While doing so, the display device 22 displays graphics 37 that help the user in guiding the catheter tip 60 to a desired location within the human body. Once the catheter 50 is placed in the desired location, the user removes the signal generating assembly 16 while the position of the catheter 50 is maintained. The user then attaches medicine and nutritional delivery tubes to the y-port connector 44 for introducing fluids into the body for medical treatment.

It should also be understood that, in alternate embodiments, the electronic catheter unit of the present invention need not include the generator position control device described above. Here, the assemblers may measure each catheter and disregard each catheter that is too long or too short. It should be appreciated that other assembly processes and mechanisms may be used to control the proper location of the field generator 58 relative to the catheter tip 60.

It should also be appreciated that the tubing assembly, electronic catheter unit and catheter position guidance system of the present invention can be used in a variety of catheter procedures and applications. These procedures may involve the treatment of the gastrointestinal tract, cardiovascular system or other portions of the human body. These procedures may involve treatment of humans by physicians, physician assistants, nurses or other health care providers. In addition, these procedures may involve treatment of other mammals and animals by veterinarians, researchers and others.

The present invention, in one embodiment, includes a tubing assembly and signal generator for an electronic catheter unit of a catheter position guidance system. The tubing assembly and signal generator are used in conjunction with other components of the system to assist the user in performing a catheter placement procedure. The tubing assembly has a position controller which enables the system to be used with catheters of variable lengths. Therefore, the tubing assembly and the position controller, used in conjunction with the catheter position guidance system of the present invention, provide an enhancement in medical treatment.

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. 

The invention is claimed as follows:
 1. A tubing assembly for use in conjunction with a signal generator having a connector, a magnetic field generator and at least one elongated electrical conductor coupling the connector to the magnetic field generator, the elongated electrical conductor having a diameter, the tubing assembly comprising: a tubular insulator having a first end connected to the connector, a second end, an internal diameter and an external diameter, the internal diameter being substantially equal to or greater than the diameter of the elongated electrical conductor; a union device having a first end and a second end, the first and second ends each having an internal diameter and an external diameter, the first end of the union device being coupled to the second end of the tubular insulator, the internal diameter of said first end being substantially equal to or larger than the external diameter of the second end of the tubular insulator; a fastener securing the tubular insulator to a user-selectable location on the union device; a tubular connector having a plurality of ends, a first one of the ends being attached to the second end of the union device; a catheter having a first end and a second end, said first end being attached to a second one of the ends of the tubular connector; and an end member attached to the second end of the catheter.
 2. The tubing assembly of claim 1, wherein the union device includes an elongated neck positioned between the first and second ends of the union device.
 3. The tubing assembly of claim 1, wherein the union device includes a gripping member positioned between the first and second ends of the union device.
 4. The tubing assembly of claim 1, wherein the union device includes a position controller.
 5. The tubing assembly of claim 1, wherein the union device includes a stop.
 6. The tubing assembly of claim 1, wherein the tubular connector has a medicine branch, a feeding branch, a connection branch and a plurality of movable arms.
 7. The tubing assembly of claim 1, wherein the catheter includes an external surface having a plurality of designated unit markings uniformly spaced along the catheter.
 8. The tubing assembly of claim 1, wherein the end member includes a first portion having a collar and a second portion having a rounded shape, the first portion defining a passage and an opening. 